A down-hole environment such as, for example, an oil or gas well in an oilfield, may expose equipment used down-hole, such as packers, blow out preventers, drilling motor, drilling bit, and the like, to conditions which may affect the integrity or performance of the element and tools.
Where the article is an element having a rubber or plastic part or coating, down-hole conditions may cause, for example, swelling by uptake of hydrocarbon oil, water or brine, or other materials found in such environments, and which can thereby weaken the structural integrity of the element or cause the element to have poor dimensional stability, resulting in difficulty in placing, activating, or removing the element. Likewise, where the element includes metallic components, these components may be exposed to harsh, corrosive conditions due to the presence of materials such as hydrogen sulfide and brine, which may be found in some down-hole environments.
Protective coatings are therefore desirable on such down-hole elements, particularly coatings having improved barrier properties to resist exposure to a variety of different environmental conditions and materials found in down-hole environments.